The invention relates to an electronic switching apparatus for switching ultra high frequency television signals, for example, of the order of 1 to 2 GHz, comprising at least two paths each of which can, as required, either amplify or block a signal applied to its input, each path comprising an impedance matching input stage and an amplifier stage.
A switching device of this type is particularly used in arrangements for receiving television signals by satellite. In accordance with the standard defined for such receptions, two channels are transmitted simultaneously in accordance with two different directions of polarization and the receiver head end transmits the two signals each corresponding to one of the directions of polarization to a tuner. The switching device according to the invention can be used for selecting the reception of one of these two signals.
An electronic switching device for switching VHF television signals is known from the document U.S. Pat. No. 4,397,041. The arrangement described in this document functions at relatively low frequencies of the order of several MHz. It comprises two paths each loaded by half a winding of the transformer. If a switching device according to this document is to be used at ultra-high frequencies of signals to be received via satellite, which signals are located in the 1 to 2 GHz band, serious problems of impedance mismatching will occur because the load winding of the path which must be cut off represents a poorly controlled impedance in parallel with the other path.